Trapdoor-operating mechanism



l AS6253 March 111 g 1924;,

F. A. KUNKEL TRAPDOOR OPERATING MECHANISM Filed July 5 Patented ar. 11, 192.

FRANK A. KUNKEL, O1? MARION TOWNSHIP, PLYMOUTH COUNTY, IOWA.

TRAPDOOR-OPERATING MECHANISM.

Application filed July 3,

To all whom it may concern:

Be it known that I, FRANK A. KUNKEL, a citizen of the United States of America, and resident of Marion Township, Plymouth county, Iowa, have invented a new and useful Trapdoor-Operating Mechanism, of which the following is a specification.

An object of this invention is to provide improved means for operating, particularly for opening, heavy trap-doors such as are found in driveways of grain elevator buildings, warehouses,piers and the like.

A further object of this invention is to provide improved means for adjusting the leverage in lifting and operating mechanisms for trap-doors.

My invention consists in the construction, arrangement and combination of elements hereinafter set forth, pointed out in the claims and illustrated by the accompanying drawing, in which Figure 1 is a plan showing my improved mechanism applied as required for practical use. Figure 2 is a side elevation of the same, portions being broken away to reveal elements and the dotted lines showing the parts in open position.

In the construction of the device as shown the numeral designates generally a floor of a driveway in which an opening (outlined by the line 11) is formed, said opening normally being closed by a trap-door 12 hinged at one side to the floor and forming a continuation thereof. A rooloshaft 13 is laid in a groove in the floor 10 parallel with and adjacent to the axis of the hinges of the door 12 and an arm 14 on one end of said rock-shaft is arched upwardly slightly and extended over the central portion of said door at right angles to said axis. The rockshaft 13 is journaled in bearings 15 fixed to the floor 10. The outer end of the arm 14 is slidingly confined, in a clip 16 fixed to the door 12. A frame consisting of parallel side bars 17, 18 and cross-bars 19, 20 is laid on the floor 10 and extends across the outer end portion of the rock-shaft 13 and said frame is secured to the floor 10 by hooked clips 21 fixed to the floor and engaging over the cross-bars 19, 20. A yoke 22 is pivoted to the side-bars 17, 18 and rises be tween them. A yoke 23 is pivoted to end portions of the side-bars 17, 18 and is spaced from the yoke 22. A lever handle 24 is fixed at one end to the outer end of the rock-shaft 13 (or may be formed integrally 1922. Serial No. 572,568.

therewith) and is bent somewhat between itsends. A clip 25 is pivoted on the closed central portion of the yoke 22 and is connected pivotally by twin rods 26, 27 to the lever handle 24, said connection between the twin rods and handle being by a bolt 28 passed through any of the holes 29 in the handle. The several holes 29 in the handle provide means for adjusting the connection with the twin rods 26, 27 thereby adjusting the leverage. A retractile coil spring 30 connects the closed central portion of the yoke 23 to the clip 25. Thus is provision made to utilize the tension of the spring 30 to aid in lifting the door 12, the direct and immediate lifting of the door being effected by manual force applied to the lever handle 24 and communicated through the rockshaft 13 and arm 14 to the clip 16. The door 12 is limited in its opening movement to an arc of substantially ninety degrees by engagement of the arched or oif-set inner portion of the arm 14 with the adjacent edge of the floor 10. Also the door is held in open position by the tension of the spring 30 supplemented by the weight of the lever handle 24 which has been carried over a dead center and into contact with the twin rods 26, 27. The operating parts may be varied as to length and the spring varied as to tension to accommodate difierent weights of trap-doors. As the door moves in either direction through an arc the clip 16 slides on the outer end of the arm 14, thus providing a sliding connection between the door and arm of the rock-shaft.

I claim as my invention- 1. In a trap-door operating mechanism, the combination with a floor and a trap door disposed in hinged relation adjacent an opening through said floor, of bearings disposed in transverse alinement on the upper side of said floor above the plane of the hinged edge of said door, a rock-shaft mounted in said bearings and extending parallel with and above said edge, an arm on one end of said shaft extending toward and above the central portion of said door, sliding connections between said arm and door, a lever handle carried on the opposite end of said shaft and extending at an oblique angle to and above the plane of said floor adjacent one end of said door, said handle being adapted to be moved through an arc across a dead center, a retractile coil spring anchored at one end to said floor and fiexi ble connections between the opposite end of said spring and said handle,

I 2. In a trap-door operating mechanism, the combination with a floor and a trap door disposed in hinged relation adjacent an opening through said floor, of bearings disposed in transverse alinement on the upper side of said floor above the plane of the hinged edge of said door, a rock-shaft mounted in said bearings and extending parallel with and above'said edge, an arm on'one end of said shaft extending toward and above the central portion of said door, sliding connections between said arm and door,a lever han'dle carried on the opposite end of said shaft and extending at an oblique angle to and above the plane of said floor adjacent one end of said door, said handlebeing adapted "to be moved through an arc across a dead center, a retractile coil spring anchored at one end to said floor, a

pivoted yoke rising from said floor between the spring and shaft, the opposite end of said spring being secured to the upper end of said yoke and pivotal, connections be tween said yoke and handle.

yokes pivoted in said frame, a clip carried by one yoke, a retractile coil spring connecting said clipto the other yoke, and twin rods connecting said clip adjustably to the I lever.

Signed at Le vMars, in the county of Plymouth and State of Iowa, this 28 day or June, 1922. 7

' r. A. KUNKEL. 

